1. Field of the Invention
This invention relates generally to videoconferencing systems and more particularly to a system capable of utilizing pre-existing peer-to-peer videoconferencing applications and a multi-point control unit (MCU) managed by a participant-controllable content delivery interface.
2. Description of the Related Art
Conferencing devices are used to facilitate communication between two or more participants physically located at separate locations. Devices are available to exchange live video, audio, and other data to view, hear, or otherwise collaborate with each participant. Common applications for conferencing include meetings/workgroups, presentations, and training/education. Today, with the help of videoconferencing software, a personal computer with an inexpensive camera and microphone can be used to connect with other conferencing participants. The operating systems of some of these machines provide simple peer-to-peer videoconferencing software, such as MICROSOFT'S NETMEETING application that is included with MICROSOFT WINDOWS based operating systems. Alternatively, peer-to-peer videoconferencing software application can be inexpensively purchased separately. Motivated by the availability of software and inexpensive camera/microphone devices, videoconferencing has become increasingly popular.
Video communication relies on sufficiently large and fast networks to accommodate the high information content of moving images. Audio and video data communication also demand adequate bandwidth as the number of participants and the size of the data exchange increase. Even with compression technologies and limitations in content size, sufficient bandwidth for multi-party conferences is not readily available using common and inexpensive transport systems.
FIGS. 1A-1C illustrate the content transfer requirements for each participant in a two, three, or four member conference, respectively. As can be seen, each member must send and receive content from each of the other participants. As the number of participants increase, so too does the connection requirements for each participant. For example, where there are two participants each participant requires two connections, where there are three participants each participant requires four connections, where there are four participants each participant requires six connections, and so on. As a consequence of the increased connection requirements, the systems supporting these requirements become more sophisticated and of course, more expensive. Thus, most inexpensive videoconferencing systems limit a participant to connecting with only one other member, i.e. a peer-to-peer connection.
Devices are available to address the excessive amount of connections. A Multi-point Control Unit (MCU) helps resolve the connection issue by establishing a central location for connection by all participants. An MCU is an external device that efficiently allows three or more participants to establish a shared conference. A peer-to-peer connection is established between the MCU and each conference participant using the participant videoconference software. FIGS. 2A-2C illustrates the connection reduction offered by a MCU as compared to the connection requirements of FIGS. 1A-1C. In particular, for two participants, each participant has two connections, for three participants, each participant has three connections, for four participants, each participant has four connections, and so on. While the MCU reduces the amount of outgoing connections each participant must manage, the incoming content transfer requirements are still too high to manage large conferences.
An MCU can offload more processing from the participant's machine by reducing the content it sends to each participant. For example, an MCU can choose to send only the content of the participant who is speaking. Alternately, the MCU can choose to combine participant audio and video signals. When combining video, signal loss will occur as each participant's video signal is scaled to a smaller fraction of its original size. Often MCUs will combine only the audio signals so that all members can be heard, and send only the video signal of the active speaker. By using these offloading techniques, less information needs to be transferred to each participant.
A shortcoming of the MCU is the lack of flexibility allowed for the conference participants. That is, there is a small fixed set of configuration features offered to the participants. In addition, the MCU is often managed by a remote administrator that further limits any dynamic configuration of the conference presentation by the participants. Yet another, limitation in using peer-to-peer software with the MCU is that the peer-to-peer software is not designed to provide features for a multi-participant conference environment. More particularly, the peer-to-peer software applications, whether included with an operating system or purchased separately, is limited to features provided exclusively for peer-to-peer conferencing environments.
As a result, there is a need to solve the problems of the prior art to provide a method and apparatus for enabling a multi-participant videoconferencing environment where the participants have peer-to-peer videoconferencing software such that the videoconferencing environment allows the user flexibility in defining configuration features and content delivery.